... 2.3 years warranty for heat pipe solar water heater 3,Simple installation 4,Anti-freezing -40 ... degree Newest heat pipe split pressurized solar water heater(CE,SABS,Keymark,EN12976)Technical data Heat ... diameter Anti-freezing ≤ (-)40°CCharacteristicsThe heat pipe solar collector consists of heat pipe glass vacuum tube, ... heat pipe split pressurized solar water heater(CE,SABS,Keymark,EN12976)